GM Truck Club
THE PREMIER CHEVY TRUCK & SUV FORUM
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Page 2 of 2 FirstFirst 12
Results 11 to 16 of 16
  1. #11
    Legend

    Join Date
    Sep 2010
    Location
    everett, massachusetts
    Posts
    1,321

    Default

    I have checked into this voltage issue. the PCM turns OFF the alternator when in the fuel saving mode. this is not at all good for the battery . the constant charge / discharge will shorten the batteries life . GM however can claim that these vehicles get XXX MPG.

    Another reason for ME to not buy these vehicles.

  2. #12

    Default

    Over charging the battery is even worse for it, and whether you know it or not your present truck allows the battery to charge and discharge in the same manner only it uses the voltage regulator to do this instead of freewheeling the alternator. Doing the same thing only in a different manner and making the engine more efficient.

  3. #13
    Sr. Engineer
    Join Date
    Oct 2010
    Location
    Indianapolis, In
    Posts
    487

    Default

    Nothing is free. The fuel you save while not charging will HAVE to be spent on the extra power used to recharge. They get to claim fuel savings in that mode and I am sure they do but you can't stay there forever and when you come out of it, extra fuel wil be used to drive an alternator under a heavier load while recharging.
    Seems a poor choice to stress alternator and battery for PR and have the customer still pay for the gas and replace components prematurely. I would love to see the test data that proves me wrong.
    2000 GMC YUKON SLT, 5.3L tow pkg, G80 rear/w 3.73 gear

  4. #14
    Legend

    Join Date
    Sep 2010
    Location
    everett, massachusetts
    Posts
    1,321

    Default

    I agree with this 100% ! your stressing out both the battery and alternator.

    The regulator over many decades now has been controlling the battery charging quite well.

    I get 7 years on my batteries. then replace. working or not.

  5. #15

    Default

    I'm sure the alternator is working correctly. The defective battery was charged for 90 minutes and then load tested. The electrical system had to also be tested to be sure that the battery was getting a charge. GM builds 9 million vehicles a year, that is a lot of batteries and to get a bad one out of the box is quite probable. The heat in South Florida really beats up the lead acid batteries. If you get five years from any battery you're lucky. I've lived in South Florida for 22 years and of all the cars and trucks I've own an average of three-four years is normal. I've not have paid a full price on a battery for years. I buy the six year warranty units and they always get prorated.

  6. #16

    Default

    What you're seeing is "normal". I watched mine and it seemed to only charge at 12 volts. Took it back to the dealer he told me it was OK. Two days later the battery went dead. They fixed something it now has 100,000 miles on it and reads higher than 13v most of the time.

Page 2 of 2 FirstFirst 12

Similar Threads

  1. Voltage Gauge fell over?
    By Bama Z71 in forum GM Electrical Tech
    Replies: 8
    Last Post: 02-06-2011, 10:15 PM
  2. battery gauge malfunction
    By britrailer in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 9
    Last Post: 11-29-2010, 01:25 PM
  3. Voltage gauge issue/question
    By hihoslva in forum Chevy Suburban Forum (GMC Yukon XL)
    Replies: 6
    Last Post: 04-12-2010, 08:03 PM
  4. battery voltage reading
    By cordgrass in forum General Chevy & GM Tech Questions
    Replies: 3
    Last Post: 03-15-2010, 09:40 AM
  5. help 98 s10 battery draining low voltage
    By noahraysanders in forum Chevy S10 Forum (GMC Sonoma)
    Replies: 1
    Last Post: 12-03-2009, 10:56 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •